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You searched for: subject:"Solar Arrays"
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[texts]Method and apparatus for measuring frequency and phase difference - NON
A system for deriving direct digital indications of frequency and phase difference between two incoming pulse trains adaptable for collision avoidance systems or the like. A pair of radar beams 152 and 152A are directed toward a target 153 and corresponding beams 154 and 154A returning therefrom are detected. A digital difference circuit 110 forms a pulse train 66 from the Doppler shift frequencies of each beam pair having a repetition rate functionally related to the difference in magnitude of ...
Keywords: SOLAR ARRAYS; STEPPING MOTORS; PATENTS
Downloads: 105
[texts]Comparison of the Effects of using Tygon Tubing in Rocket Propulsion Ground Test Pressure Transducer Measurements - Farr, Rebecca A.
This paper documents acoustics environments data collected during liquid oxygen- ethanol hot-fire rocket testing at NASA Marshall Space Flight Center in November- December 2003. The test program was conducted during development testing of the RS-88 development engine thrust chamber assembly in support of the Orbital Space Plane Crew Escape System Propulsion Program Pad Abort Demonstrator. In addition to induced environments analysis support, coincident data collected using other sensors and meth...
Keywords: SOLAR ARRAYS; LENSES; PHOTOVOLTAIC CELLS; CONCENTRATORS; SPACE MISSIONS; HARDWARE
Downloads: 128
[texts]Solid-state non-volatile electronically programmable reversible variable resistance device - NON
A solid-state variable resistance device (10) whose resistance can be repeatedly altered by a control signal over a wide range, and which will remain stable after the signal is removed, is formed on an insulated layer (14), supported on a substrate (12) and comprises a set of electrodes (16a, 16b) connected by a layer (18) of material, which changes from an insulator to a conductor upon the injection of ions, covered by a layer (22) of material with insulating properties which permit the passage...
Keywords: ELECTRIC POTENTIAL; LOADS (FORCES); PHOTOVOLTAIC CELLS; SOLAR ARRAYS; PATENTS
Downloads: 121
[texts]STS FACILITY AND EQUIPMENT DESIGN PLAN. VOLUME 81: COMMUNICATIONS - NON
No Abstract Available
Keywords: CRYSTAL GROWTH; RIBBONS; SILICON; DESIGN ANALYSIS; EQUIPMENT SPECIFICATIONS; SOLAR ARRAYS
Downloads: 519
[texts]Review of the Bioastronautics Data Book - Bottomley, T. A., Jr.
No Abstract Available
Keywords: ELECTRICAL PROPERTIES; PANELS; SOLAR ARRAYS; CONFERENCES; ELECTRIC POWER; MANAGEMENT PLANNING
Downloads: 149
[texts]Developing A Web-based User Interface for Semantic Information Retrieval - Berrios, Daniel C.
While there are now a number of languages and frameworks that enable computer-based systems to search stored data semantically, the optimal design for effective user interfaces for such systems is still unclear. Such interfaces should mask unnecessary query detail from users, yet still allow them to build queries of arbitrary complexity without significant restrictions. We developed a user interface supporting semantic query generation for Semanticorganizer, a tool used by scientists and enginee...
Keywords: SOLAR ARRAYS; INTERNATIONAL SPACE STATION; ELECTRIC POTENTIAL; SPACE STATION POWER SUPPLIES; ORBITS; SHORT CIRCUITS
Downloads: 69
[texts]Pressure distribution on Joukowski wings - Blumenthal, O
The hydrodynamics and mathematical models as applied to the potential flow about a Joukowski wing are presented.
Keywords: RECTENNAS; SOLAR POWER SATELLITES; SYSTEMS ANALYSIS; FAILURE ANALYSIS; SOLAR ARRAYS; SPACECRAFT COMMUNICATION; STRUCTURAL DESIGN
Downloads: 133
[texts]EFFECTS OF SUPERPLASTICITY OF TITANIUM AND ITS ALLOYS AND THE USE OF THIS PHENOMENON IN WELDING IN THE SOLID STATE - SHORSHOROV, M. K.
SUPER PLASTICITY OF TITANIUM AND SOME OF ITS ALLOYS ARE DISCUSSED, AS WELL AS THE POSSIBILITY OF USING TITANIUM FOR INTENSIFYING THE PROCESS BY WHICH A COMPOUND IS FORMED IN THE SOLID STATE. IT WAS ASSUMED THAT INTENSIFICATION IN WELDING DEPENDS ON THE SPEED OF THE MOVEMENT OF STRUCTURAL DEFECTS, INTERGRAIN SLIP, AND DIFFUSION. THE STUDY WAS PERFORMED ON THE IMASH-5 S-65, A DEVICE FOR HIGH TEMPERATURE METALLOGRAPHY WITH A CHAMBER ADAPTED FOR WELDING AND DILATOMETRIC PROCESSES.
Keywords: MISSION PLANNING; RENDEZVOUS SPACECRAFT; SOLAR ELECTRIC PROPULSION; SOLAR ARRAYS; SPACECRAFT POWER SUPPLIES; SYSTEMS ANALYSIS; WEIGHT ANALYSIS
Downloads: 94
[texts]Theoretical study of the upper ionosphere based simultaneous data from the ISIS satellites and from the CNET incoherent backscatter sounder - Fleury, L
No Abstract Available
Keywords: HYDROGENATION; SEMICONDUCTORS (MATERIALS); SILANES; SOLAR ARRAYS; PARTICLE SIZE DISTRIBUTION; REACTION KINETICS; REACTOR TECHNOLOGY; TEMPERATURE MEASUREMENT
Downloads: 104
[texts]SiC/SiC Composites for Applications Above 2600 F - DiCarlo, James A.
Using data from panels with 2D woven architectures,t his presentation describes progress in identifying advanced constituent materials and processes for achieving a high conductivity SiC/SiC composite system with long-term structural life under oxidizing conditions at 2600 degrees F. A key factor for this progress is the development of approaches at NASA GRC that allow the constituent SiC fiber and SiC matrix to display high thermal conductivity, high creep-rupture resistance and high microstruc...
Keywords: SPACECRAFT CHARGING; EXTERNAL SURFACE CURRENTS; CONFERENCES; SPACE PLASMAS; COMPUTERIZED SIMULATION; TETHERLINES; SOLAR ARRAYS; CHARGE DISTRIBUTION
Downloads: 126
[texts]Drives and benefits overview - Mcintyre, S. D
The major technology issues for an advanced orbital transfer vehicles (OTV) engine to be used in conjunction with a space based, reusable orbit transfer vehicle are discussed. The results of the space station studies as they relate to the OTV and the ground rules and guidelines for a reusable OTV vehicle study are reviewed. The technology drives and benefit categories such as mission versatility, increased reliability or reduced cost are presented...
Keywords: INFRARED SPECTRA; TEMPERATURE MEASUREMENT; MODULES; PERFORMANCE TESTS; SOLAR ARRAYS; TRANSPARENCE; EFFICIENCY; IRRADIANCE; REFLECTANCE; SPECTRUM ANALYSIS
Downloads: 112
[texts]Development of a microbalance suitable for space application - Patashnick, H.
The tapered element oscillating microbalance (TEOM), an ultrasensitive mass measurement device which is suitable for both particulate and vapor deposition measurements is described. The device can be used in contamination measurements, surface reaction studies, particulate monitoring systems or any microweighing activity where either laboratory or field monitoring capability is desired. The active element of the TEOM consists of a tube or reed constructed of a material with high mechanical quali...
Keywords: LOW COST; SILICON; SOLAR ARRAYS; CARBON; COMPUTER PROGRAMS; FREE ENERGY; MOLECULAR DYNAMICS; MOLECULAR ENERGY LEVELS
Downloads: 129
[texts]Inertial navigation/calibration/precise time and frequency capabilities - Galloway, L. M.
The Aerospace Guidance and Metrology Center was conceived in 1959 to be the US Air Force Inertial Navigation and Metrology Center. This paper will show the mission capabilities of the Inertial Navigation Maintenance Center and the Air Force Measurement and Standards Laboratory. Highlighted will be the precise time and frequency program developed by AGMC to support Air Force precise time and frequency requirements worldwide...
Keywords: CONFERENCES; UTILITIES; FLAT PLATES; SOLAR ARRAYS; ELECTRIC NETWORKS; FAILURE ANALYSIS; PHOTOVOLTAIC CELLS; REFINING; SILICON; THIN FILMS
Downloads: 99
[texts]Retrieval of Polar Stratospheric Cloud Microphysical Properties from Lidar Measurements: Dependence on Particle Shape Assumptions - Reichardt, J.
A retrieval algorithm has been developed for the microphysical analysis of polar stratospheric cloud (PSC) optical data obtained using lidar instrumentation. The parameterization scheme of the PSC microphysical properties allows for coexistence of up to three different particle types with size-dependent shapes. The finite difference time domain (FDTD) method has been used to calculate optical properties of particles with maximum dimensions equal to or less than 2 mu m and with shapes that can be...
Keywords: DATA ACQUISITION; POINTING CONTROL SYSTEMS; PERFORMANCE TESTS; HUBBLE SPACE TELESCOPE; SOLAR ARRAYS
Downloads: 82
[texts]Land Surface Temperature Measurements from EOS MODIS Data - Wan, Zhengmin
We have developed a physics-based land surface temperature (LST) algorithm for simultaneously retrieving surface band-averaged emissivities and temperature from day/night pairs of moderate resolution imaging spectroradiometer (MODIS) data in seven thermal infrared bands. The set of 14 nonlinear equations in the algorithm is solved with the statistical regression method and the least squares fit method...
Keywords: SOLAR ARRAYS; SOLAR CELLS; MARS PATHFINDER; ANGLES (GEOMETRY); INCIDENCE; DATA PROCESSING; DATA ACQUISITION
Downloads: 179
[texts]A compendium of hypokinetic and hypodynamic animal studies - Pleasant, L. G.
This compendium organizes and summarizes the scientific literature dealing with the study of hypokinetic and hypodynamic animal studies. It includes both American and foreign research papers.
Keywords: SEMICONDUCTORS (MATERIALS); SILANES; SILICON; SOLAR ARRAYS; PLANT DESIGN; POWDER (PARTICLES); TEST FACILITIES
Downloads: 233
[texts]Method for ambiguity resolution in range-Doppler measurements - NON
A method for resolving range and Doppler target ambiguities when the target has substantial range or has a high relative velocity in which a first signal is generated and a second signal is also generated which is coherent with the first signal but at a slightly different frequency such that there exists a difference in frequency between these two signals of Delta f(sub t). The first and second signals are converted into a dual-frequency pulsed signal, amplified, and the dual-frequency pulsed si...
Keywords: ELECTRIC BATTERIES; ELECTRIC DISCHARGES; ELECTRIC POTENTIAL; SOLAR ARRAYS; DESIGN ANALYSIS; EARTH ORBITAL ENVIRONMENTS
Downloads: 154
[texts]Intelligent Pilot Aids for Flight Re-Planning in Emergencies - Pritchett, Amy R
Experimental studies were conducted with pilots to investigate the attributes of automation that would be appropriate for aiding pilots in emergencies. The specific focus of this year was on methods of mitigating automation brittleness. Brittleness occurs when the automatic system is used in circumstances it was not designed for, causing it to choose an incorrect action or make an inaccurate decision for the situation...
Keywords: ELECTRIC PROPULSION; PROPULSION SYSTEM CONFIGURATIONS; MARS MISSIONS; LASER POWER BEAMING; SOLAR ARRAYS; COST EFFECTIVENESS; SPACECRAFT DESIGN
Downloads: 100
[texts]Effects of Hydrogen on GRCop-84 - Ellis, David L.
This report is a section of the final report on the GRCop-84 task of the Constellation Program and incorporates the results obtained between October 2000 and September 2005 when the program ended. GRCop-84 contains approximately 5.5 wt% Nb. Nb can react with H and embrittle easily. Previous work had indicated the thermodynamic possibility that Cr 2 Nb could react with H and form niobium hydrides in the presence of high pressure H such as seen in the Space Shuttle Main Engine...
Keywords: MISSION PLANNING; SPACE FLIGHT; PAYLOADS; ORBIT INSERTION; LAUNCHING; PARACHUTE DESCENT; SEQUENCING; SOLAR ARRAYS; ACCURACY; DEPLOYMENT; PROCEDURES
Downloads: 82
[texts]Fabrication feasibility study of a 30 watt pound roll-up solar array Quarterly report, 27 Jun. - 30 Sep. 1967 - King, W. G
Structural design and analysis of 30 watt/pound roll-up solar array
Keywords: FABRICATION; FEASIBILITY; PRODUCT DEVELOPMENT; SOLAR ARRAYS; SOLAR CELLS; STRUCTURAL DESIGN; PRODUCT DEVELOPMENT; SOLAR CELL; STRUCTURAL DESIGN
Downloads: 106
[texts]Representativeness Uncertainty in Chemical Data Assimilation Highlight Mixing Barriers - Lary, David Joh
When performing chemical data assimilation the observational, representativeness, and theoretical uncertainties have very different characteristics. In this study we have accurately characterized the representativeness uncertainty by studying the probability distribution function (PDF) of the observations. The average deviation has been used as a measure of the width of the PDF and of the variability (representativeness uncertainty) for the grid cell...
Keywords: LOW EARTH ORBITS; SPACECRAFT CHARGING; SOLAR CYCLES; SOLAR ARRAYS; GROUND TESTS; ELECTRIC CURRENT; HIGH VOLTAGES
Downloads: 81
[texts]Design of a walking robot - Whittaker, William
Carnegie Mellon University's Autonomous Planetary Exploration Program (APEX) is currently building the Daedalus robot; a system capable of performing extended autonomous planetary exploration missions. Extended autonomy is an important capability because the continued exploration of the Moon, Mars and other solid bodies within the solar system will probably be carried out by autonomous robotic systems...
Keywords: CONTROL STABILITY; CONTROLLERS; HUBBLE SPACE TELESCOPE; POINTING CONTROL SYSTEMS; SOLAR ARRAYS; COMPUTERIZED SIMULATION; FLAPPING
Downloads: 359
[texts]Robust UHTC for Sharp Leading Edge Applications - Levine, Stanley R.
Ultrahigh temperature ceramics have performed unreliably due to material flaws and attachment design. These deficiencies are brought to the fore by the low fracture toughness and thermal shock resistance of UHTCs. If these deficiencies are overcome, we are still faced with poor oxidation resistance as a limitation on UHTC applicability to reusable launch vehicles. We have been addressing the deficiencies of UHTCs for the past year via a small task at GRC that is part of the 3rd Gen TPS effort...
Keywords: STRUCTURAL DESIGN; SOLAR CELLS; SOLAR ARRAYS; WINGS; STRETCHING; MECHANICAL ENGINEERING; DEEP SPACE 1 MISSION
Downloads: 114
[texts]Effects of Thermomechanical History on the Tensile Behavior of Nitinol Ribbon - Lach, Cynthia L.
Shape memory alloys (SMAs) have enormous potential for a wide variety of applications. A large body of work exists on the characterization of the microstructure and stress-strain behavior of these alloys, Nitinol (NiTi) in particular. However, many attributes of these materials are yet to be fully understood. Previous work at NASA Langley Research Center (LaRC) has included fabrication of hybrid composite specimens with embedded Nitinol actuators and modeling of their thermomechanical behavior...
Keywords: INTERNATIONAL SPACE STATION; SOLAR ARRAYS; SPACE STATION POWER SUPPLIES; GIMBALS; ELECTRIC GENERATORS; PHOTOVOLTAIC CONVERSION
Downloads: 100
[texts]Very low cost thin film CdS-Cu2S solar cell development using chemical spraying - Samara, G. A.
A chemical spray process for the production of thin film CdS-Cu2S solar cells is discussed that is projected to cost less than 60/kW in very large scale production. The average efficiency of these cells has been improved from less than 0.3% in 1971 about 4.5% at present. Further developments for the process are considered to raise the efficiency, and to attain long life stability.
Keywords: LOW COST; MANUFACTURING; SILICON; SOLAR ARRAYS; CRYSTAL GROWTH; HEAT TREATMENT; RECRYSTALLIZATION; SHEETS
Downloads: 168
[texts]Analytical modeling of spacecraft power systems - Cassinelli, J
Power system components are reviewed. Battery and solar array models are discussed. Shunt regulators, dc-dc converters, and cabling are also discussed.
Keywords: ARC HEATING; PRODUCTION ENGINEERING; REFINING; SILICON; HIGH TEMPERATURE TESTS; SOLAR ARRAYS; SYSTEMS ANALYSIS; TEST FACILITIES
Downloads: 169
[texts]Environmental impact analysis with the airspace concept evaluation system - Augustine, Stephen
The National Aeronautics and Space Administration (NASA) Ames Research Center has developed the Airspace Concept Evaluation System (ACES), which is a fast-time simulation tool for evaluating Air Traffic Management (ATM) systems. This paper describes linking a capability to ACES which can analyze the environmental impact of proposed future ATM systems. This provides the ability to quickly evaluate metrics associated with environmental impacts of aviation for inclusion in multi-dimensional cost-be...
Keywords: MARS PATHFINDER; MARS ROVING VEHICLES; DUST; SOLAR ARRAYS; MARS ENVIRONMENT; SPACECRAFT SHIELDING; TRANSPARENCE; DEPOSITION
Downloads: 96
[texts]Surface topographical changes measured by phase-locked interferometry - Lauer, J. L.
An electronic optical laser interferometer capable of resolving depth differences of as low as 30 A and planar displacements of 6000 A was constructed to examine surface profiles of bearing surfaces without physical contact. Topological chemical reactivity was determined by applying a drop of dilute alcoholic hydrochloric acid and measuring the profile of the solid surface before and after application of this probe...
Keywords: NICKEL HYDROGEN BATTERIES; REGENERATIVE FUEL CELLS; BROMINE; CHLORINE; HYDROGEN; OXYGEN; SOLAR ARRAYS
Downloads: 99
[texts]On-pad crew safety: Modifications to operations and hardware to improve crew escape times - Knaff, P. R
No Abstract Available
Keywords: ENERGY POLICY; LOW COST; SILANES; SOLAR ARRAYS; GAS CHROMATOGRAPHY; HYDROGENATION; PHOTOVOLTAIC CONVERSION
Downloads: 88
[texts]An Extensible Schema-less Database Framework for Managing High-throughput Semi-Structured Documents - Maluf, David A.
Object-Relational database management system is an integrated hybrid cooperative approach to combine the best practices of both the relational model utilizing SQL queries and the object oriented, semantic paradigm for supporting complex data creation. In this paper, a highly scalable, information on demand database framework, called NETMARK is introduced. NETMARK takes advantages of the Oracle 8i object-relational database using physical addresses data types for very efficient keyword searches o...
Keywords: SOLAR ARRAYS; VAPOR DEPOSITION; THIN FILMS; SUBSTRATES; SOLAR CELLS; ELECTRICAL PROPERTIES; MODULATION; POLYCRYSTALS; FABRICATION
Downloads: 100
[texts]Bubble Measuring Instrument and Method - NON
Method and apparatus are provided for a non-invasive bubble measuring instrument operable for detecting, distinguishing, and counting gaseous embolisms such as bubbles over a selectable range of bubble sizes of interest. A selected measurement volume in which bubbles may be detected is insonified by two distinct frequencies from a pump transducer and an image transducer. respectively. The image transducer frequency is much higher than the pump transducer frequency...
Keywords: MARS (PLANET); MARS MISSIONS; MARS PATHFINDER; MARS ENVIRONMENT; MARS ATMOSPHERE; MISSION PLANNING; DUST; SOLAR ARRAYS
Downloads: 98
[texts]Assessment of the international workshop on CdS solar cells - Boer, K. W
General problems relating to the basic understanding of CdS/Cu2S solar cell operation, to material aspects of the cell and to manufacturing methods and cell engineering are discussed.
Keywords: CRYSTAL GROWTH; RIBBONS; SEMICONDUCTING FILMS; SILICON; PHOTOVOLTAIC CELLS; PRODUCTION ENGINEERING; SOLAR ARRAYS
Downloads: 125
[texts]The recirculation flow pattern of a VTOL lifting engine - Schwantes, E
A method is developed to predict theoretically the increase of temperature due to wind recirculation in the inlet of a VTOL aircraft lift engine exhausting normally to the ground. A method for calculating the velocities in the recirculation flow is presented. The laws of spread of buoyant plumes is used to calculate the temperatures within the recirculated flow. The three regions of the propulsion jet are identified as: (1) the free jet, (2) the wall jet, and (3) the zone of separation of the wa...
Keywords: ATTITUDE (INCLINATION); LIQUID METALS; SOLAR ARRAYS; DIELECTRIC PROPERTIES; ELECTRIC CONTACTS; GALLIUM; PERFORMANCE TESTS; RING STRUCTURES
Downloads: 142
[texts]American Space History: Legacies, Questions, and Opportunities for Future Research - Siddiqi, Asif A
In the 35 years since astronauts Neil A. Armstrong and Buzz Aldrin set foot on the Moon, no space achievement has quite captured people s imaginations as Apollo. Thirty-five years after that singular event, the specter of Apollo still looms large as a benchmark for all that came later. In the context of the current inertia of the American space program-the Space Shuttle temporarily grounded while astronauts take to orbit in Russian rockets for unimaginative tours of the International Space Stati...
Keywords: SOLAR ARRAYS; SOLAR ENERGY; SOLAR POWERED AIRCRAFT; SUNLIGHT; PHOTOVOLTAIC CELLS; SOLAR CELLS; INDUSTRIES; ORGANIZATIONS; RESEARCH AIRCRAFT
Downloads: 264
[texts]Preliminary feasibility assessment for Earth-to-space electromagnetic (Railgun) launchers - Rice, E. E.
An Earth to space electromagnetic (railgun) launcher (ESRL) for launching material into space was studied. Potential ESRL applications were identified and initially assessed to formulate preliminary system requirements. The potential applications included nuclear waste disposal in space, Earth orbital applications, deep space probe launchers, atmospheric research, and boost of chemical rockets. The ESRL system concept consisted of two separate railgun launcher tubes (one at 20 deg from the horiz...
Keywords: ELECTRIC BATTERIES; SOLAR ARRAYS; SPACECRAFT POWER SUPPLIES; COMMUNICATION CABLES; REGULATORS; VOLTAGE CONVERTERS (DC TO DC)
Downloads: 346
[movies]NASA Connect - ISS - ISS Basics - NASA LaRC Office of Education
NASA Connect segment exploring the International Space Station. The video explains the basic facts and statistics about the ISS.
Keywords: NASA Connect; International Space Station; ISS; Solar Arrays; Space Stay; Atlantis; Destiny Laboratory; Research; ISS Components
Downloads: 1,273
[texts]Message Passing vs. Shared Address Space on a Cluster of SMPs - Shan, Hongzhang
The convergence of scalable computer architectures using clusters of PCs (or PC-SMPs) with commodity networking has become an attractive platform for high end scientific computing. Currently, message-passing and shared address space (SAS) are the two leading programming paradigms for these systems. Message-passing has been standardized with MPI, and is the most common and mature programming approach...
Keywords: CONSTRAINTS; CORDAGE; KEVLAR (TRADEMARK); SPACECRAFT EQUIPMENT; SOLAR ARRAYS; LAUNCH VEHICLE CONFIGURATIONS
Downloads: 95
[texts]SOLAR ELEMENTS BASED ON HETEROJUNCTION OF P-TYPE GAAS(1-X)PX AND N-TYPE GAAS - CHEBAN, A. G.
MEASURED DARK CURRENT-VOLTAGE CHARACTERISTICS, LIGHT CURRENT-VOLTAGE CHARACTERISTICS UNDER LOAD, AND SPECTRAL RESPONSE CURVES ARE GIVEN FOR PHOTOSENSITIVE ELEMENTS PREPARED BY LIQUID EPITAXIAL GROWTH OF P-TYPE GAAS/1-X/P/X/ ON AN N-TYPE GAAS SUBSTRATE. DUE TO THE ABSENCE OF A CONDITIONING SURFACE LAYER, 30% OF THE RADIATION INCIDENT ON THE WORKING SURFACE IS REFLECTED, YIELDING AN EFFICIENCY OF 6 TO 7%...
Keywords: CONTROL EQUIPMENT; INSTRUMENT ORIENTATION; SATELLITE-BORNE INSTRUMENTS; SOLAR ARRAYS; BREADBOARD MODELS; CIRCUITS; SYSTEMS ENGINEERING
Downloads: 79
[texts]Antimatter propulsion, status and prospects - Howe, Steven D.
The use of advanced propulsion techniques must be considered if the currently envisioned launch date of the manned Mars mission were delayed until 2020 or later. Within the next thirty years, technological advances may allow such methods as beaming power to the ship, inertial-confinement fusion, or mass-conversion of antiprotons to become feasible. A propulsion system with an ISP of around 5000 s would allow the currently envisioned mission module to fly to Mars in 3 months and would require abo...
Keywords: ENCAPSULATING; GASKETS; LAMINATES; FABRICATION; FLAT PLATES; LIFE (DURABILITY); MODULES; SOLAR ARRAYS; ADHESIVES; COST ESTIMATES; ELASTOMERS
Downloads: 126
[texts]Viking Lander antenna deployment mechanism - Hopper, K. H.
One of the mechanisms that is included in the configuration of the Viking Mars Lander is an antenna dish deployment mechanism which utilizes a mechanical escapement device for controlling deployment. The criteria require that the mechanism be capable of deploying the antenna under a wide range of aiding and retarding winds after landing on Mars but must limit the acceleration during deployment and latching of the antenna...
Keywords: ACTUATORS; MECHANICAL DRIVES; SOLAR ARRAYS; MECHANICAL ENGINEERING; PERFORMANCE TESTS; SERVICE LIFE; STRUCTURAL DESIGN
Downloads: 151
[texts]Information content in spectral calculations - Abarbanel, S.
No Abstract Available
Keywords: DEGRADATION; TEFLON (TRADEMARK); TELEMETRY; SOLAR ARRAYS; SOLAR CELLS; SOLAR MAXIMUM MISSION; SPACECRAFT POWER SUPPLIES; ADHESIVES; CHARGED PARTICLES; PREDICTIONS; RADIATION DOSAGE
Downloads: 65
[texts]High-Rate Strong-Signal Quantum Cryptography - Yuen, Horace P
Several quantum cryptosystems utilizing different kinds of nonclassical lights, which can accommodate high intensity fields and high data rate, are described. However, they are all sensitive to loss and both the high rate and the strong-signal character rapidly disappear. A squeezed light homodyne detection scheme is proposed which, with present-day technology, leads to more than two orders of magnitude data rate improvement over other current experimental systems for moderate loss.
Keywords: ELECTRONIC PACKAGING; DURABILITY; ACRYLIC RESINS; ENCAPSULATING; COST EFFECTIVENESS; SOLAR ARRAYS; INSULATION; POLYMERIZATION; FABRICATION; GLASS FIBERS; SILICON POLYMERS
Downloads: 51
[texts]ON THE EFFECT OF RELIABILITY OF SIMULATION RESULTS ON THE METHODOLOGY OF FLIGHT TESTING AND SIMULATION - KAESTNER, R
VARIOUS METHODS OF FLIGHT SIMULATION ARE DESCRIBED AND A COMPARISON OF THE RESULTS OBTAINED BY FLIGHT SIMULATORS ARE DISCUSSED. THE VAK 191 B AIRCRAFT IS USED AS AN EXAMPLE OF TYPICAL TAKEOFF AND LANDING PERFORMANCE FOR STOL AIRCRAFT. DIAGRAMS OF THE AIRCRAFT ATTITUDE CONTROL DURING TRANSITION PHASES FOLLOWING TAKEOFF AND DURING, LANDING APPROACH ARE PROVIDED. TECHNIQUES USED BY THE TEST PILOT IN CONDUCTING THE FLIGHT TESTS ARE DESCRIBED.
Keywords: COMMUNICATION SATELLITES; VIBRATORY LOADS; JETTISON SYSTEMS; PANELS; SOLAR ARRAYS; SYSTEMS ENGINEERING; PERFORMANCE TESTS; QUALITY CONTROL; SATELLITE-BORNE INSTRUMENTS; THERMAL RESISTANCE
Downloads: 62
[texts]Moderate lift-to-drag aeroassist - Florence, D. E.
Significant performance benefits are realized via aerodynamic braking and/or aerodynamic maneuvering on return from higher altitude orbits to low Earth orbit. This approach substantially reduces the mission propellant requirements by using the aerodynamic drag, D, to brake the vehicle to near circular velocity and the aerodynamic lift, L, to null out accumulated errors as well as change the orbital inclination to that required for rendezvous with the Space Shuttle Orbiter...
Keywords: ELECTRIC POWER SUPPLIES; HISTORIES; MANNED SPACECRAFT; SOLAR ARRAYS; SPACECRAFT PROPULSION; ELECTRIC POTENTIAL; ENERGY CONVERSION EFFICIENCY; RELIABILITY; THERMOELECTRIC GENERATORS
Downloads: 136
[texts]VIEWS REGARDING THE VALIDITY OF RESULTS FROM SIMULATION TESTING IN COMPARISON WITH THE RESULTS FROM ACTUAL FLIGHT TEST - SCHULZ, U.
A COMPARISON OF THE VALIDITY OF RESULTS OBTAINED BY FLIGHT SIMULATION WITH RESULTS OBTAINED FROM ACTUAL FLIGHT TESTS IS PRESENTED. THE BACKGROUND FOR THE DEVELOPMENT OF THE SIMULATOR IS DISCUSSED. THE TECHNIQUES FOR CONDUCTING THE SIMULATION ARE OUTLINED. EXAMPLES OF FLIGHT SIMULATION OPERATIONS ARE DEVELOPED. RESULTS OF THE COMPARISON INDICATE GOOD CORRELATION BETWEEN SIMULATION AND FLIGHT TEST DATA.
Keywords: SOLAR ARRAYS; THERMAL CYCLING TESTS; VACUUM CHAMBERS; FATIGUE TESTS; SPACE ENVIRONMENT SIMULATION; TEST FACILITIES; THERMAL VACUUM TESTS
Downloads: 114
[texts]Flow Visualization by Elastic Light Scattering in the Boundary Layer of a Supersonic Flow - Herring, G. C.
We demonstrate instantaneous flow visualization of the boundary layer region of a Mach 2.5 supersonic flow over a flat plate that is interacting with an impinging shock wave. Tests were performed in the Unitary Plan Wind Tunnel (UPWT) at NASA Langley Research Center. The technique is elastic light scattering using 10-nsec laser pulses at 532 nm. We emphasize that no seed material of any kind, including water (H2O), is purposely added to the flow...
Keywords: SOLAR ARRAYS; THERMAL CYCLING TESTS; SOLAR CELLS; ENERGY CONVERSION EFFICIENCY; EARTH ORBITAL ENVIRONMENTS; STRUCTURAL DESIGN; PHOTOVOLTAIC CONVERSION; FABRICATION; CHARGED PARTICLES
Downloads: 116
[texts]Acoustical properties of highly porous fibrous materials - Lambert, R. F
Highly porous, fibrous bulk sound absorbing materials are studied with a view toward understanding their acoustical properties and performance in a wide variety of applications including liners of flow ducts. The basis and criteria for decoupling of acoustic waves in the pores of the frame and compressional waves in the frame structure are established. The equations of motion are recast in a form that elucidates the coupling mechanisms...
Keywords: POLYMERIZATION; SOLAR ARRAYS; STOICHIOMETRY; SEMICONDUCTORS (MATERIALS); SILICON; SILICON POLYMERS; SOLAR ENERGY CONVERSION; ENERGY POLICY; LOW COST; MASS SPECTROSCOPY; PHOTOVOLTAIC CELLS
Downloads: 211
[texts]National Research Council Dialogue to Assess Progesss on NASA's Human Exploration Systems and Mobility Capability Roadmap Development: General Background and Introduction - Inman, Thoma
General Background and Introduction of Capability Roadmaps: Agency Objective. Strategic Planning Transformation. Advanced Planning Organizational Roles. Public Involvement in Strategic Planning. Strategic Roadmaps and Schedule. Capability Roadmaps and Schedule. Technology and Capability Readiness Levels. Relationships Between Roadmaps. Purpose of NRC Review. Capability Roadmap Development (Team Progress to Date).
Keywords: ALGORITHMS; SOLAR GENERATORS; ELECTRICITY; ENERGY STORAGE; FLYWHEELS; SPACECRAFT POWER SUPPLIES; BUS CONDUCTORS; CONTROLLERS; SOLAR ARRAYS; SOLAR CELLS
Downloads: 79
[texts]Wing Torsional Stiffness Tests of the Active Aeroelastic Wing F/A-18 Airplane - Lokos, William A.
The left wing of the Active Aeroelastic Wing (AAW) F/A-18 airplane has been ground-load-tested to quantify its torsional stiffness. The test has been performed at the NASA Dryden Flight Research Center in November 1996, and again in April 2001 after a wing skin modification was performed. The primary objectives of these tests were to characterize the wing behavior before the first flight, and provide a before-and-after measurement of the torsional stiffness...
Keywords: MOLECULAR GASES; VACUUM CHAMBERS; MASS SPECTROMETERS; MOLECULAR IONS; SOLAR ARRAYS; SPACE PLASMAS; GAS IONIZATION; DESORPTION; WATER VAPOR; PLASMA CLOUDS; CAPACITANCE
Downloads: 87
[texts]Geostatistical Methods For Determination of Roughness, Topography, And Changes of Antarctic Ice Streams From SAR And Radar Altimeter Data - Herzfeld, Ute C
The central objective of this project has been the development of geostatistical methods fro mapping elevation and ice surface characteristics from satellite radar altimeter (RA) and Syntheitc Aperture Radar (SAR) data. The main results are an Atlas of elevation maps of Antarctica, from GEOSAT RA data and an Atlas from ERS-1 RA data, including a total of about 200 maps with 3 km grid resolution. Maps and digital terrain models are applied to monitor and study changes in Antarctic ice streams and...
Keywords: PHOTOVOLTAIC CONVERSION; SOLAR ARRAYS; SOLAR CELLS; THIN FILMS; SINGLE CRYSTALS; PROPULSION SYSTEM CONFIGURATIONS; SOLAR ELECTRIC PROPULSION; TECHNOLOGY UTILIZATION
Downloads: 85
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